Approximately 30% of cardiovascular (CV) mortality is potentially preventable through the adoption of healthy behaviors, such as regular physical activity, healthy diet, and not smoking. Adoption of these behaviors is influenced by the community environments where patients reside and variation in these environments is associated with disparities in CV mortality. Eliminating these placed-based disparities has been elusive because a community is comprised of multiple interrelated parts, including the physical and the social environment, which are further influenced by contextual factors such as state policies, urbanicity, and socioeconomic status. As such, although aspects of the physical and social community environment have been independently associated with lower CV morbidity and mortality, interventions aiming improve a single one have had variable effects. This proposal requests three years of support for Dr. Brita Roy to complete targeted training in complex systems modeling ? a set of methods that effectively captures these dynamic community relationships ? to explore the various effects changes in the physical and social environments of a community together have in shaping CV health-related behaviors. These methods are critical tools for implementation science, as they enable the translation of current evidence towards real-world interventions by elucidating the mechanisms by which change occurs, better anticipating results before testing expensive interventions. Dr. Roy is a board-certified general internist with a strong quantitative background in engineering and with expertise in healthy behavior promotion. This proposal describes a career development plan that will allow Dr. Roy to develop skills in group model building (i.e., a participatory approach to model development) applied to two complementary methods necessary to understand the complexity of community environments: (1) agent- based modeling, a method that characterizes bidirectional resident-environment interactions; and (2) system dynamics modeling, a method that captures positive and negative dynamic feedback loops among many community factors. Dr. Roy will develop these methodologic skills and hone other skills needed to become an independent investigator under the guidance of Drs. Harlan Krumholz, an expert in CV health outcomes research; Leslie Curry, an expert in implementation science; Marcella Nunez-Smith, an expert in community-engaged research and CV health disparities; and Margaret Weeks, an expert in group model building. The primary mentor, Dr. Krumholz, has been Dr. Roy?s mentor on her current K12 award and has successfully mentored multiple K awardees. Completion of this award will help Dr. Roy achieve her long-term goal of establishing herself as an independent investigator who develops interventions to effectively mitigate place-based disparities in CV health using assets-based, participatory approaches. The knowledge gained and models created in this proposal will be used to support an R21 and an R01 proposal that estimate the most efficient set of interventions to achieve desired health outcomes in two local, low-resource communities.